This invention relates to the monitoring of a process for the partial oxidation of a carbon-containing fuel, particularly coal, by an oxygen-containing gas in a reactor under high pressures and temperatures. In a preferred form, it relates to a process for monitoring a gasifier from which the product gas is removed at the top of the gasifier and the formation of solid deposits at or near the exit thereof and in proximate heat exchange equipment may be encountered.
Many carbon-containing fuels are of mineral origin, and often contain, in addition to carbon and hydrogen, varying quantities of inorganic incombustible material. The latter material is a by-product of the process of combustion or oxidation, and, depending on characteristics such as density and size of the particular particle, and the reactor configuration and conditions, may undergo a rough separation therein into particles called "flyash" (lighter) and "slag" (denser). The flyash particles may be removed with the combustion gas or product synthesis gas through a zone or conduit where the gas and particles undergo heat exchange, while the denser materials may collect as a molten slag in the hearth of the reactor and are discharged downward through an outlet or orifice in the hearth, in some cases, into a water bath. In some instances, product gas, slag, and flyash are removed together from one outlet, but may undergo a similar later separation.
A real concern in processes, particularly where product gas is removed "overhead" through a vertically disposed conduit or heat exchange zone, is that the slag separation will not be complete and "stalagmite" deposits will tend to grow or creep outward or upward from slag depositing at the outlet of the gasification zone. Blockage of the gasifier outlet and the entrance and initial segment of the quench zone by such mechanism represents a potentially catastrophic situation and requires shutdown of the operation, an obviously unsatisfactory circumstance. Accordingly, to prevent such occurrences, regular monitoring of the units is practiced, and techniques, such as rapping, are employed to limit or release deposits. The invention is directed to an improved method of monitoring gasifier and heat exchange zone stalagmite deposit formation during full operation of the process.